ST. LOUIS — March had not been turning out to be a very good month for star freshmen in the NCAA Tournament.

The tournament lost Jabari Parker when No. 14-seed Mercer stunned No. 3 Duke in the opening round on Thursday.

When No. 2-seed Kansas had its season ended prematurely by Stanford Sunday at the Scottrade Center, Andrew Wiggins, another NBA lottery pick in waiting the moment he declares himself draft eligible, was sent home.

Some 30 minutes after the Kansas game on the same floor, Kentucky would face 35-0 Wichita State and its veteran-laden team in a matchup many believed would be the end of a dysfunctional season for the Wildcats and their freshmen starting five who had endured criticism all season for being underachievers.

Despite all its talent, with a McDonald’s All-American at every position, Las Vegas had Kentucky’s group of individuals losing to Wichita State because Wichita State had the ultimate team and, as it is said, teams win championships.

As it turned out, though, Kentucky’s kids are all right.

Kentucky did more than end Wichita State’s magical undefeated season with an electrifying 78-76 win in the Midwest Regional third round to advance to a can’t-wait Sweet 16 smackdown with Louisville Thursday in Indianapolis.

More importantly, the Wildcats grew up and asserted themselves as a force in this tournament after entering it as a complete question mark.

In the 40-minute span, this classic showdown these two divergent programs treated 19,676 fans to, it felt as if you were watching Kentucky’s kids grow up in a slow-motion, time-warp video.

“They have been through so much,’’ Kentucky coach John Calipari said. “They have been attacked. They have been bludgeoned. ‘They can’t play. They are not a team. You can’t do it this way.’ But they stayed together. It makes you strong. It makes you tough as nails.’’

It has made Kentucky more dangerous than it’s been all season.

“You can see us maturing right before your eyes. It’s a sign that we can be a great team,’’ Kentucky sophomore Alex Poythress said.

There was plenty of adversity in this game, because Wichita State is good. Damn good. The Shockers led by as many as nine points in the second half. But Kentucky’s kids never folded. Not even when Wichita State’s league MVP Fred VanVleet launched a potential game-winning 3-pointer from the top of the key at the buzzer — a shot that bounded off the right side of the rim.

“Losing never entered my mind,’’ Kentucky sophomore Willie Cauley-Stein said. “But it felt like five million pounds lifted off our shoulders when that buzzer went off at the end of the game. Our team has been through a lot of stuff this year. A lot of people counted us out in the first game [against Kansas State], let alone this game.

“A lot of people said we were underdogs in this game, but I never feel like an underdog wearing this jersey. With wearing this jersey comes a lot of hate. We have a big target on our backs because of the program we play for. This proves we’re a better team than people gave us credit for being. Everyone is now to a point where they’re fitting into their roles. Now everyone is finally jelling and we’re becoming a team.”

Music to Calipari’s ears.

Sunday against Wichita State felt like the culmination of everything Calipari had been trying — often in vain — to drill into the heads of his 18-year-olds so they can experience NCAA Tournament moments like this — and maybe a few more.

“This was great joy in seeing a group of young men come together and start figuring this thing out,’’ Calipari said. “It took longer than I’d hoped.”

There was a “but’’ in there, but it was left unsaid.

“Here’s what’s happened with this team: They are now putting themselves in a position where they are accepting roles how they have to play, so we’re becoming a better team,’’ Calipari said. “Individuals are losing themselves into the team. I just wish we had another month of the season left [to] keep playing, because we are getting better every day. I just wish this thing could extend and extend and extend … but obviously it won’t.’’